Gearing.



W. L. McDONALD & P. P. STEWART.

GEARING.

APPLICATION FILED MAR. 25. HIM.

Patented Nov, 20, 1917.

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ILL 77 $022 jmLZ l- 157 640073? W. L. MCDONALD & P. P. STEWART.

GEARING. APPLICATION FILED MAR. 25. I914- Patented N 0v. 20, 191?,

4 SHEETS-SHEET 3.

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W. L. McDONALD & P. P. STEWART.

GEARING. APPLICATION FILED mmzs. 1914.

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WILLIAM L. MCDONALD AND PAUL P. STEWART, OF CHICAGO, ILLINOIS.

' GEARING.

Specification of Letters Patent.

Patented Nov. 20 191?.

Application filed March 25, 1914. Serial No. 827,017.

To all whom it may concern: Be it known that we, WILLIAM L. McDon- ALDand PAUL P. STEWART, citizens of the United States, and residents ofChicago, in the county of Cook and State of Illinois, have inventedcertain new and useful Improvements in Gearing; and we do hereby declarethat the following is a full, clear, and exact description thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon, which form a part of this specification.

This invention relates to improvements in differential gearing, moreespecially intended for application to motor driven vehicles, andconsists of the matters hereinafter described and more particularlypointed out in the appended claims. In the more familiar type ofdifferential gearing heretofore in use, if one of the two tractionwheels driven by' the differential gearing speeds ahead of the other onaccount of losing its grip .and slips or slides as a result, thetendency is for all or substantially all of the driving force of thedriving shaft to be imparted to that wheel. Said force is thus lost ordissipated in the increased speed of the said wheel which races withouteffect, while the other wheel,

which has a traction grip, receives practically no driving force andstands still. With such differential gearing, the vehicle will not bedriven forward unless both wheels have a traction grip.

The object of this invention is to provide a differential gearing inwhich either of the traction wheels driven by the gearing will beautomatically disconnected from driving connection with the gearing theinstant that it starts to rotate more rapidly than the associatedtraction wheel, as in turning a corner, said wheel remaining thus aslong as its higher speed of rotation continues, but in which said wheelwill be automatically returned to its operative driving connection withthe gearing when its speed falls to that of its companion wheel. And iffor any reason one wheel loses, or tends to lose its traction grip, itwill only receive driving force in proportion to tl e resistance offeredby it, while the balance of the force of the differential gearing willbe imparted to the other Wheel, that is to say, to the one retaining itstraction grip. The racin'g.that may occur in the case of the ordinarydifferential gearing is therefore obviated in the improved gearing.

In the draw1ngs:

Figure 1 is a view representing a section through the improveddifferential gearing in the plane of the longitudinal central axis ofthe two part shaft of the traction wheels.

Fig. 2 is a side elevation of the same.

Fig. 3 is a view representing a section through Fig. 1, in a planeindicated by the line 3-3 thereof.

Fig. 4 is a View representing a section through Fig. 1, in a planeindicated by the line 4-4 thereof.

Fig. 5 is a view representing a side elevation of the driven gearconnected with the casing of the gearing.

Figs. 6 and 7 are views representing elevations of opposite sides of theclutch members used in the gearing.

Figs. 8 and 9 are diagrammatic views, partly in plan and partly insection, illustrating the different positions of the clutch members inthe operation of the gearing.

Fig. 10 is a sectional view similar to that shown in Fig. 1 representinga modified form of the invention.

Fig. 11 is a view representing a transverse section through Fig. 10 in aplane indicated by the line 11-l1of Fig. 10.

Fig. 12 is a View representing a section through Fig. 10 in a planeindicated by the line 1212 of Fig. 10.

Referring now to that embodiment of the invention illustrated in thedrawings and particularly in Figs. 1-9, inclusive, 10 indicates the maindrive shaft, and 11, 11, the two shafts or parts, comprising a two partdriven shaft, each of which is connected to one of the traction wheelsof the automobile or other type of vehicle to which the gearing isapplied. Each shaft or shaft part is attached to a fiat ring or head 12,having bearing in a rotative casing indicated as a whole by the numeral13, which is driven from the main drive shaft 10, and which incloses theclutch members and the devices for actuating them by means of wh ch saidcasing is operatively connected with the shaft heads.

The casing 13 consists of two cylindrical shells 14, 14, which inclosean annular chamber about the proximate ends of the shaft parts 11, 11.Each shell 14 has a flat end wall l4 which engages the outer face of ashaft head 12 and acts to retain the same in the casing. Said shell hasan annular flange 14 forming a hub bearin for a sleeve 12 fixed to theshaft head. he head 12, as shown, is attached to its associated shaftpart by means of a key 12.

18 indicates an annular plate interposed between the two shells 14 andrigidly connected thereto by means of suitable bolts which alsopreferably provide the means for connecting the shells 14 together. Saidplate may project radially beyond the easing 13 and is there provided onone side with beveled gear teeth 19, which mesh with a pinion 10 fixedon the drive shaft 10. This constitutes the driving connection betweenthe drive shaft 10 and the casing 13. The plate 18 also projectsradially into the chamber inclosed by the casing and is there providedon both sides with a set of annularly arranged cam teeth 20.

21, 21 indicate clutch members located in the casing, there being oneclutch member interposed between each shaft head 12 and the proximateset of cam teeth 20. Each clutch member consists of a fiat ring 22,rotatively mounted on its associated shaft part 11 and having teeth 24on one side adapted for engagement with similarly formed teeth 23 on theadjacent face of the shaft head 12 and having cam teeth 26 on itsopposite face adapted for engagement with the cam teeth 20 on theannular plate 18.

Each clutch member 21 is provided on its inner side with an annularflange 27, which has rotative bearing on the adjacent ends of the shaftparts 11. The two flanges are provided with longitudinally extendinglugs 28 and intermediate notches 29, the lugs of one clutch memberengaging in the notches of the other clutch member. The lugs are made ofless arcuate length than the notches in which the engage, so that alimited rotative play is permitted between the two clutch members, asclearly shown in Fig. 3. A coiled spring 30 is interposed between thetwo clutch members, said spring acting to force said clutch membersapart and bring and hold the teeth 24 of each clutch member intoengagement with the teeth 23 on its associated shaft head, the cam teeth26 being released from engagement with the cam teeth 20 on the annularplate 18, whenever the heads 12 and with them the locking rings 22 tendto travel more rapidly than the casing, as clearly shown in Fig. 8.

' The operation of the improved gearin s as follows. The rotation of theshaft 10 imparts rotative movement to the casing 13' through the beveledgear 10 and the gear teeth 19 which are fixed to the casing. Beforemovement is imparted to the casing, the clutch members are in theposition indicated in Fig. 8, namely, that position last abovedescribed. The rotative movement imparted to the casing will cause thecam teeth 20, which are rigid with the casing, to move in One directionor the other, say for example, the direction indicated by the arrow 00.This causes the cam teeth 20 to forcibly engage the cam teeth 26, asillustrated on the lower side of Fig. 9, both clutch members beingnormally engaged in this way when both traction wheels offer resistance.The action of the cam teeth fixed to the casing forces the teeth 24 oneach clutch member to operatively engage teeth 23 on their associatedshaft heads so as to positively rotate the two shaft parts as long asthere is any tendency of shaft parts to lag behind the casing, that isto say, as long as they offer resistance to rotation.

Should one traction wheel tend to speed ahead of the other, it will act,by reason of the engagement of the teeth 24 on its associated shafthead, with the teeth 23 on the associated clutch member, to carry saidclutch member forward ahead of the casing, this movement between the twoclutch members being made possible by reason of the play permittedbetween the two clutch members heretofore referred to. This brings theparts into the relative position indicated in the upper side of Fig. 8where the cam teeth 26 on the clutch member are disengaged from the camteeth 20 moving with the casing, so that the clutch member is free tomov longitudinally on the shaft away from the shaft head. This positionis continued until the free rotative movement of the lugs 28 and notches29 is taken up, after which the clutch member moves longitudinally,allowing the shaft head to move ahead of the clutch member as shown inthe upper part of Fig. 9, and this movement of the parts will continueas long as the shaft and its associated wheel tend to rotate faster thanthe casing. As soon as this wheel and shaft slow down relatively to thecasing, the parts will be again lockingly engaged with the casing,whereupon both wheels will be driven in the rotation of the casing andwith the same rotative speed.

In Figs. 10-12, inclusive, there is shown a slightly modified form ofthe invention, in which the coiled spring 30 is dispensed with and afriction band is interposed between the clutch members 21, 21 and theirrespective associated heads 12 in such manner as to normally tend tomake the said clutch members rotate with their respective heads.

In the figures referred to,severa1'of the parts are indicated by thesame numerals of reference heretofore used in connection with the likeparts of other figures. 12*, 12 indimamas cate the heads in this caseand 21, 21 the clutch members associated with said heads. Each of theheads 12 is provided on its face, adjacent its associated clutch member21*, with an annular recess 12 in which is located a flat, splitfriction band 30 Said friction band 30 is provided with fixed pins 30(there being, as shown in the drawings, two of such) which projectthrough holes or openings 30 in the associated clutch member 21 Saidpins are slightly smaller than the holes 30 through which they extend,so that a slight play is permitted between the friction band 30 and itsassociated clutch member 21, allowing free longitudinal movement of theclutch member 21.

The friction band performs substantially the same function as the coiledspring 30, heretofore referred to, and tends to carry the associatedclutch member 21 with the associated head 12 until the limited rotativeplay between the lugs 28 and notches 29 has been absorbed. Any furtherrotative movement of the associated heads will cause the teeth 23 and 24to become disengaged, as before. I

The drawings show the differential as being shaft driven and designedwith reference to the non-floating type of axle, but is equallyapplicable to any form of powerdriven differential.

While in describing the invention, we have referred to certain detailsof mechanical construction and arrangement, it is to be understood thatthe invention is in no way to be limited thereby, except as pointed outin the appended claims.

We claim as our invention:

1. A difierential gearing comprising a power driven casing, a two partdriven shaft having rotative bearing in said casing, each shaft partbeing provided with a shaft head, said casing being provided with a cammember having cam teeth, clutch rings mounted in said casing, therebeing one clutch ring interposed between each shaft head and said cammember, said clutch ring being provided with cam teeth for engagementwith the teeth of said cam member, and being provided on the other sidewith teeth for engagement with the teeth on its associated shaft head,means acting to yieldingly hold said clutch rings in operativeengagement with their respective shaft heads, and means providing forlongitudinal play of said clutch ring away from their shaft heads andfor limited, relative, rotative movement be tween said clutch rings.

2MA differential gearing comprising a power driven casing, a two partdriven shaft having rotative bearing in said casing, a clutch device foreach shaft part comprising a clutch member movable longitudinally insaid casing, said clutch member and shaft parts being provided withengaging teeth, said casing having a cam member located intermediatesaid clutch members, said cam member having a set of cam teeth for eachclutch member, said clutch member being provided with cam teeth forengagement with the cam teeth of said casing, means acting to normallyhold the teeth of each clutch member in engagement with the associatedteeth of its shaft part, and means connecting said clutch memberspermitting limited relative, rotative movement between them.

3. A differential gearing comprising a power driven casing, a two partdriven shaft, said shaft arts having bearing in said casing, a clutchdevice for each shaft part comprisin a clutch member movablelongitudinally 1n said casing, said clutch member and shaft parts beingprovided with engaging teeth and said casing having a member providedwith cam teeth, a set for each clutch member, said clutch member beingprovided with cam teeth for engagement with the cam teeth of saidcasing, means acting to normally hold the teeth of each clutch member inengagement with the as sociated teeth-of its shaft part, and meansconnecting said clutch members permitting limited, relative, rotativemovement between them.

4. A differential gearing comprising a power driven casing, a two partdriven shaft provided with heads having rotative bearing in said casing,and a cam member fixed to said casing intermediate said shaft heads,clutch rings, one for each shaft head, located on either side of saidcam member, said cam member being provided with sets of cam teeth, onefor each clutch ring, said clutch rings being capable of limitedrotative movement relative to each other in said casing and each clutchring being capa' ble of longitudinal movement between its associatedshaft head and the cam member, and yielding means acting to normallyhold said clutch rings in engagement with their associated shaft heads,but permitting said clutch rings to be disengaged when the shaft headassociated with either ring rotates ahead of the casing.

5. In differential mechanism, in combination, a driving part havingmajor clutch teeth on both sides, shiftable clutch members having majorclutch teeth on one side in mesh with teeth of the driving part, eachshiftable clutch member having minor clutch teeth on one side thereof,means carried by the respective shiftable clutch members to permit andto limit relative rotative movement of the shiftable clutch members andto allow said members to move toward and from the dr ving part, drivenparts each formed with minor clutch teeth on one side for operativeengagement with the minor clutch teeth of the respective shiftableclutch members, and yieldable means to urge the shiftable clutch membersinto mesh with the respective driven parts.

6. In differential mechanism, in combination, a driving part havingmajor clutch teeth on both sides thereof, shiftable clutch membershaving major clutch teeth on one side in mesh with teeth of the drivingpart,

- each shiftable clutch member having minor clutch teeth on one sidethereof, means carried by the respective shiftable clutch members topermit and to limit relative rotative movement of the shiftable clutchmembers and to allow said clutch members to move toward and from thedriving part, means to maintain the shiftable clutch members inalinement, driven parts each formed with minor clutch teeth on one sidefor operative engagement with the minor clutch teeth of the respectiveshiftable clutch members and yieldable means to urge the shiftableclutch members into mesh with the respective driven parts.

7 In differential mechanism, in combination, a driving part havingclutch teeth on both sides, shiftable clutch members having teeth onboth sides thereof, the teeth on one side of each shiftable clutchmember being in mesh with teeth of the driving part, means carried bythe respective shiftable clutch members to permit and to' limit relativerotative movement of the shiftable clutch members and to allow saidmembers to move toward and from the driving part, independent shafts, adriven part fixed to one end of each shaft and formed with clutch teethon one side for operative engagement with teeth of the respectiveshiftable clutch members, and yieldable means to urge the shiftableclutch members into mesh with the respective driven parts,

8. In differential mechanism, in combination, a rotatable housing, adriving part having clutch teeth on both sides thereof, shiftable clutchmembers positioned on both sides of the driving part and having clutchteeth on both sides thereof, the teeth on one side of each shiftableclutch member being in mesh with teeth of the driving part, meanscarried by the respective shiftable clutch members to permit and tolimit relative rotative movement of the shiftable clutch members and toallow said members to move toward and from the driving part, independentshafts, a drivenpart fixed to one end of each shaft and formed withclutch teeth on one side for operative engagement with teeth of therespective shiftable clutch members, and yieldable means to urge theshiftable clutch members into mesh with the respective driven parts.

9. A device of the class described, comprising a pair of coaxiallydisposed driven members, having an annular space between them, a singledriving ring dlSPOSBd concentrio with the members and extending into theannular space, devices interposed between the ring and each of themembers for operatively connecting the ring and members, means forlimiting angular movement of the device associated with one memberrelative to the device associated with the other member for the purposeset forth, and a shaft secured to each of said members.

10. A device of the class described, comprising a pair of co-axiallydisposed driven collars having an annular space between them, a singledriving ring disposed concentric with the collars and extending into theannular space, devices interposed between the ring and each of thecollars for operatively connecting the ring and collars, means forlimiting angular movementv of the device associated With one collarrelative to the device associated with the other collar for the purposeset forth, and a shaft secured to each of said collars.

11. A device of the class described, comprising a pair of co-axiallydisposed driven members having an annular space between them, a singledriving ring disposed concentric with the members and extending into thannular space, devices carried with the ring interposed between the ringand each of the members for operatively connecting the ring and members,means for limiting angular movement of the device associated with onemember relative to the device associated with the other member for thepurpose set forth, and a shaft secured to each of said members.

12. A device of the class described, comprising a pair of co-axiallydisposed driven members having an annular space between them, a singledriving ring disposed concentric with the members and extending into theannular space, sleeves interposed between the ring and each of themembers for operatively connecting the ring and members, means forlimiting angular movement of the sleeve associated with one memberrelative to the sleeve associated with the other member for the purposeset forth, and a shaft secured to each of said members,

13. A device of the class described, comprising a pair of co-axiallydisposed driven members having an annular space between them, a singledriving ring disposed concentric with the members and extending into theannular space, sleeves interposed between the ring and each of themembers for operatively connecting the ring and members, means carriedby the sleeves for limiting angular movement of the sleeve asso ciatedwith one member relative to the sleeve associated with the other memberfor the purpose set forth, and a shaft secured to each of said members.

14. A device of the class described, comprising a pair of co-axiallydisposed driven sleeve associated with the other member for the purposeset forth, and a shaft secured 15 to each of said members.

In testimony, that we claim the foregoing as our invention we affix oursignatures in the presence of two witnesses, this 20th day of March A.D. 1914:.

WILLIAM L. MoDONALD. PAUL P. STEWART.

Witnesses:

GEO. R. WILKINs, T. H. ALrREns.

